You are correct about the 1400 ppm/us. This is where a nominal JTF will give a residual jitter of 0.1UIpp when the input transition density is 0.5.
 
If the transition density is 0.3 (repeating D30.3), the maximum df/dt that will give a residual jitter of 0.1UIpp with the nominal JTF is 840 ppm/us (1400 ppm/us * 0.3/0.5).  The informative max df/dt of 850 ppm/us that is in the spec was derived using the D30.3 pattern.
 
Guillaume

From: owner-t10@t10.org [mailto:owner-t10@t10.org] On Behalf Of Jenkins, Mike
Sent: Thursday, May 22, 2008 3:49 PM
To: Alvin.Cox@seagate.com; t10@t10.org
Subject: RE: Reminder, SAS PHY WG call, May 22, 10:00am CDT

All,

 

Regarding T10/08-248r0 presented on the call this morning, I believe it was Bruce Johnson who asked about whether the proposal adequately stressed delta-F/delta-T.  FWIW, it seems that extending Guillame’s analysis on slides 7-9 shows that the peak dF/dt for the prescribed SJ is about 1400 ppm/usec, independent of the modulation frequency.  Hence, it seems this test comfortably bounds the earlier proposed 1250 ppm/usec SSC limit.

 

Regards,

Mike

From: owner-t10@t10.org [mailto:owner-t10@t10.org] On Behalf Of Alvin.Cox@seagate.com
Sent: Wednesday, May 21, 2008 10:28 AM
To: t10@t10.org
Subject: Reminder, SAS PHY WG call, May 22, 10:00am CDT

 


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Webex information:
https://seagate.webex.com/seagate
Topic: SAS-2 PHY WG
Date: Thursday
Time: 10:00 am, Central Daylight Time
Meeting number: 826 515 680
Meeting password: 6gbpsSAS

Agenda:

1. Letter ballot comment resolution:
        a.  Update on receiver testing. [Witt, Newman]
        b.  External mini-SAS Cable keying
        c.  Please identify any additional concerns not addressed yet.        


Alvin Cox
Seagate Technology, LLC
Cell 405-206-4809
E-Mail  alvin.cox@seagate.com